Wind: A Breath of Heart OVA

Description:

Kazenone City, it is a city that made people feel nostalgic and wonder.
It was also the home country of Okano Makoto and his little sister, Hinata. They came back this town in order to look for their mother who had disappeared suddenly. Their friends and childhood friends welcomed their return. Makoto began to notice something important through the encounter with them. With the tone of a harmonica, and with their thoughts in their hearts, the fantastic tale began in this mysterious town.
(Source: AnimeNfo)